1. Field of the Invention
The present invention relates to an attaching method for a magnetic head used in a camera, and to an attachment for the same, in which the magnetic head contacts a magnetic recording layer of a photographic film to perform magnetic recording and/or reproduction.
2. Description of the Related Art
A photographic film having a magnetic recording layer is known. The magnetic recording layer is formed such that a magnetic material is applied to an opposite face of a photographic emulsion face. It is possible to record magnetic information in the magnetic recording layer. As the magnetic information, there are a frame number, a film sensitivity, a photographable number, a product name, and so forth which are specified at the time of manufacturing. When a photograph is taken, the magnetic information is read out to be used for setting a photographic condition. At the same time, various conditions of photographing are recorded in the magnetic recording layer.
In a camera which employs the photographic film having the magnetic recording layer, a magnetic head for performing magnetic recording and/or reproduction is provided. It is conventional that the magnetic head is attached to a film supporting plate which supports the back of the photographic film positioned at an exposure position. The film supporting plate keeps flatness of an exposure face of the photographic film.
FIG. 4 shows a conventional attachment portion of the magnetic head used for a camera. Behind a photographic film 11 positioned at the exposure position, namely at an above portion of the photographic film 11 in the drawing, a film supporting plate 13 is disposed. The film supporting plate 13 supports the photographic film 11 to keep flatness of an exposure face thereof. A magnetic head 14 is attached to a head base 15 so as to protrude from a front face of the head base 15. The magnetic head 14 is fixed to the film supporting plate 13 from its back side. The film supporting plate 13 is formed with an opening 16 for baring the magnetic head 14. The head base 15 holding the magnetic head 14 is positioned such that a protrusion amount of the magnetic head 14 relative to the opening 16 becomes a prescribed protrusion amount A.
When the protrusion amount of the magnetic head 14 is the prescribed amount A, the magnetic head 14 comes into contact with the magnetic recording layer of the photographic film 11 in a suitable pressure. Then, an adhesive is applied so as to extend from the periphery of the head base 15 to the back of the film supporting plate 13. This adhesive is hardened so that an adhesive portion 17 is formed. In this way, the head base 15 is fixed in a state that its front face is supported by the rear face of the film supporting plate 13.
The adhesive portions 17 are formed at plural places around the head base 15. The adhesive portions 17 are generally formed at two places being opposite with each other. As the adhesive forming the adhesive portion 17, for example, an ultraviolet-curing adhesive is used. The ultraviolet-curing adhesive has flowability in a normal state, and is hardened by radiation of the ultraviolet lays. Incidentally, a protrusion amount B of the magnetic head 14 relative to the head base 15 is determined in accordance with the prescribed protrusion amount A and a thickness of the film supporting plate 13.
As to the above-mentioned method in which the front of the head base 15 is fixed so as to be supported by the back of the film supporting plate 13, the head base 15 protrudes toward the back side of the film supporting plate 13 by a thickness of itself. By the way, it is very difficult to thin the thickness of the film supporting plate 13 which is an injection-molded article. The limit of this thickness is about 1.0 mm. Thus, with respect to the camera containing the film supporting plate 13 to which the magnetic head 14 is attached, it is necessary to widen a containing space in a direction of the thickness of the film supporting plate 13. Accordingly, there arises a problem in that the camera is prevented from being thinned.